Semjon Adlaj

Researcher at the Division of Stability Theory and Mechanics of Controlled Systems
Department of Mechanics of the A.A. Dorodnitsyn Computing Center
Russian Academy of Sciences, Moscow, Russia

Tel/Fax: +7 499 135 3590/6159, e-mail:

Several, chronologically ordered, fundamental publications:

1. Classification and investigation of stability of tether equilibria in proximity to a circularly orbiting satellite (in Russian). A monograph in 94 pages, written in 2011.

2. Iterative algorithm for computing an elliptic integral (in Russian) // Issues on Motion Stability and Stabilization. Moscow, CCRAS 2011: 104-110.

3. Multiplication and division on elliptic curves, torsion points and roots of modular equations. An article in 24 pages, written in 2014. Two relevant short papers by Helmut Ruhland are The inverse of the modular invariant and Constructing equalities.

4. An analytic unifying formula of oscillatory and rotary motion of a simple pendulum (dedicated to 70th birthday of Jan Jerzy Slawianowski) // Proceedings of International Conference “Geometry, Integrability, Mechanics and Quantization”, Varna, Bulgaria, 2014, June 6-11. Printed by “Avangard Prima”, Sofia, Bulgaria, 2015: 160-171.

5. An arithmetic-geometric mean of a third kind! A 15-page paper, written in 2015, containing “perfect” formulae for calculating three kinds of Complete Elliptic Integrals, with an addended 16th page, exhibiting typical troubles of common software in calculating said integrals.

6. Torque free motion of a rigid body: from Feynman wobbling plate to Dzhanibekov flipping wingnut. A 14-page paper, written in 2017, where a symmetric (in the moments of inertia) expression for the rate of precession is obtained, as well as, the relevance of constructing Galois critical axis (for describing the motion of both “the twisting tennis racket” and “Dzhanibekov flipping wingnut”) is shown.

Selected workshops and conferences:

1. (4th) International Young Researchers Workshop on Geometry, Mechanics and Control, Ghent, Belgium:
Tether equilibria in a linear parallel force field presented on 2010.01.12.

2. International Scientific Conference on Mechanics “6th Polyakhov Readings”, St. Petersburg, Russia:
Mechanical interpretation of negative and imaginary tension of a tether in a linear parallel force field presented on 2012.02.02.

3. International Conference on Differential Equations and Dynamical Systems, Suzdal', Russia:
Isoperimetric problem singularities presented on 2012.07.03.
Applying singularity theory to investigating stability of isoperimetric problem solutions presented on 2014.07.08.

4. International Conference on Mathematical Control Theory and Mechanics, Suzdal', Russia:
Back to the pendulum for an exact explicit solution! presented on 2015.07.03.

5. International Conference on Polynomial Computer Algebra, St. Petersburg, Russia:
Modular polynomial symmetries presented on 2014.04.16.
New unexpected solutions to well-known differential equations presented on 2015.04.15.
Dzhanibekov’s flipping nut and Feynman’s wobbling plate presented on 2016.04.20.

6. International Workshop on Computer Algebra, Dubna, Russia:
Iterative algorithm for computing an elliptic integral presented on 2011.06.03.
Highly efficient arithmetic of elliptic curves presented on 2012.05.23.
Elliptic and coelliptic polynomials presented on 2014.05.21.
Spin to wobble calculation and symbolic integration presented on 2016.05.24.

Few excerpts and highlights:

1. A point of order 8.
2. A fundamental theorem on rotation (in Russian).
3. Four special values of the Modular Invariant.
4. Duality of equilibria of a Simple Pendulum.
5. A heptagon constructed!
6. Triple-pair invariance theorem (in Russian).

Few works, retrieved from the past millennium:

1. On Rubik's Cube (in Russian).

Few widely-applied interdisciplinary (but non-technical) concepts, explained to curious practitioners:

1. Performance of Binary Tests. A 4-page article, explaining the dual-concepts of sensitivity and specificity.
2. The Monty Hall problem settled. Examples of hidden assumptions behind short answers to ill-posed questions.

International cooperation:

1. Ohira Tech is the first company in the world to implement (a pilot version of) the rotating celestail sphere.

Announcement of a scientific seminar in cooperation with the open club “Mathematics as Science Langauage”.

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